The present invention relates to wiring ducts, or wireways, for supporting and holding bundles of electrical conductors interconnecting diverse components in control panels and electrical cabinets.
The present invention is an improvement on the structure disclosed and claimed in U.S. Pat. No. 3,906,146 which contemplates a modular wiring duct system made of interlocking duct modular units which, when disposed end-to-end, provide a wiring duct of an appropriate length. Each modular unit consists of a molded base portion provided with appropriate stiffening ribs and with mounting apertures, and having at each end appropriate interlocking means for connection to another modular unit disposed in alignment therewith. A sidewall is formed along the edge of the base portion by a row of elongated relatively slender pins provided with an enlarged head, such that a relatively large area opening is provided between two consecutive pins for the passage of electrical conductors through the sidewalls. The electrical conductors are retained in the opening as a result of the interference provided by two adjacent enlarged pin heads preventing the electrical conductors from slipping off the opening until the cover is placed on the duct.
The pins are molded with an appropriate cross section, preferably circular, such as to provide a smooth rounded contact with the insulation of the electrical conductors, and such as to be easily manually deflected laterally in any direction, while still being provided with considerable holding power for the conductors disposed in the duct. Preferably yet, the pins are molded with a slight taper from bottom to top such as to have an increased strength where most required, namely at the root of the pins where they are attached to the base.
The pins are mounted in appropriate apertures disposed along each of the parallel sides of the base portion and the end of each pin mounted on the base portion has a tapered projecting portion snapped into the aperture in the base portion for providing sturdy mounting and ease in assembly. Any length of wiring ducts may be provided by mounting the modular units end-to-end or at right angle for forming T- and elbow, or L-connections. In addition, a corner unit forming part of the system is provided for installation where it is desired to close an end of a duct or to provide an L-connection with apertured sidewalls. An appropriate cover is part of the system to provide a closure for the wiring ducts used in electrical installations.
By omitting one of the sidewalls, the structure provides fanning strips and the like, and, in addition to having many applications in the electrical equipment wiring art, the structure may be used as a holding and distribution duct for fluid hoses and the like, or as a holder for a plurality of articles such as strings, ropes, smoking pipes, etc., and as racks for small tools, neckties and the like.